1. Field of the Invention
The present invention relates to a method and an apparatus for controlling a bi-directional pump of a gas boiler in which a shock noise generated when the bi-directional pump is switched from a rest mode or a hot-water mode to a heating mode, is not produced to enable the gas boiler to operate in quiet.
2. Description of the Prior Art
Generally, a gas boiler heats water by using the heat which is generated while the gas is burning in a burner, and then heated water circulates through a heating pipe installed in a room to heat the room. Also, the gas boiler supplies a user with hot water when the user wants to utilize the hot water.
Namely, the gas boiler adopts a bi-directional pump which includes an inflow opening into which heated water flows, two outflow openings from which the water flowing into the inflow opening flows out along water flow paths selected by the user, and a switching ball which controls the water flow paths.
After the water which is heated depending on the mode selected by the user flows through one of the pipe conduits of the bi-directional pump, the heated water flows out from the pipe conduit to heat the inside of the room. Or the heated water flows out from another pipe conduit to supply the user with the hot water.
FIG. 1 is a configuration diagram for showing a schematic configuration of a conventional gas boiler which adopts a bi-directional pump.
As shown in FIG. 1, a gas boiler includes a gas inflow pipe 11, a gas valve 12, a burner 13, a flue 14 and an exhaust fan 15.
Gas valve 12 is installed inside of gas inflow pipe 11 into which external gas flows, and adjusts the pressure of the gas which is supplied to burner 13. Burner 13 mixes the gas flowing into gas inflow pipe 11 with air, and burns the mixed gas. A flue 14 discharges a burned exhaust gas, and exhaust fan 15 forces flue 14 to discharge the exhaust gas the moment exhaust fan 15 sucks in air to supply the air to burner 13.
Also, the gas boiler includes a heating water withdrawal pipe 16, a water tank 17, a bi-directional pump 18, an heat exchanger 19, a heating water supply pipe 20, a water supplemental-pipe 21, a supplemental-water valve 22, a tap water supply pipe 23, a hot-water supply pipe 24 and a flow switch 25.
Heating water withdrawal pipe 16 withdraws heating water from a heating pipe laying inside of a room (not shown) which executes the heating. Water tank 17 is installed in connection with heating water withdrawal pipe 16, and temporarily stores returning heating water. Bi-directional pump 18 circulates the heating water. Heat exchanger 19 heats water to heat the inside of a room. Heating water supply pipe 20 supplies heated water to a heating exhaust pipe.
Water supplemental-pipe 21 discharges the heating water, and supplemental-water valve 22 is installed inside of water supplemental-pipe 21. When hot water is required to be utilized, tap water supply pipe 23 supplies heat exchanger 19 with tap water which is not subjected to heating.
Hot water supply pipe 24 discharges the water which is heated by heat exchanger 19, and flow switch 25 senses the flow of the tap water while the user is utilizing the hot water.
Hereinafter, an operation of the gas boiler having the configuration described above, is described.
Bi-directional pump 18 circulates the heating water which is withdrawn from the heating pipe arrangement of each of the rooms via heating water withdrawal pipe 16, and which is temporarily stored in water tank 17. Then, the heating water flows into heat exchanger 19. Next, after the heating water is heated while passing through heat exchanger 19 to which the heat generated by burning the gas is supplied, the heating water is supplied to the heating pipe arrangement of each of the rooms via bi-directional pump 18 and via heating water supply pipe 20.
While the user is utilizing the hot water, the tap water which is not subjected to heating flows into heat exchanger 19 via tap water supply pipe 23 to be heated by exchanging the heat with the heating water, and is then supplied to the user via hot-water supply pipe 24. At this time, flow switch 25 senses the flow of the tap water and provides a controller with a sensing signal which indicates that the hot water is being utilizing.
In a hot-water mode as described above, the revolution direction of a bi-directional pump 18 is in opposition to that found in a heating mode, and the heating water which flows out from heat exchanger 19 does not circulate through the pipe laying of each of the rooms via heating water supply pipe 20 but rather, the direction of the water flow is changed by bi-directional pump 18 to flow into heat exchanger 19 via a roundabout pipe 26.
Consequently, the heating water in heat exchanger 19 maintains a high temperature and heat exchanger 19 efficiently heats the water.
FIG. 2 is a circuit diagram for illustrating a driving of the bi-directional pump shown in FIG. 1. As illustrated in FIG. 2, bi-directional pump 18 is controlled by a first relay RL1 and a second relay RL2. In order for bi-directional pump 18 to operate in the heating mode, after first relay RL1 turns off, second relay RL2 is switched over to the heating mode and first relay RL1, successively, turns on. In order that bi-directional pump 18 operates in the hot-water mode, after first relay RL1 turns off, second relay RL2 is switched over to the hot-water mode and first relay RL1 returns to the turn-on state.
A description of a structure and an operation of bi-directional pump 18 follows.
FIG. 3 is a lateral cross-sectional view for showing a structure of the bi-directional pump shown in FIG. 1. FIG. 4 is a front cross-sectional view for showing the structure of the bi-directional pump shown in FIG. 1. As shown in FIGS. 3 and 4, bi-directional pump 18 includes a casing 41, an impeller 42, a bi-directional pump electromotor 43, first and second sleeves 44 and 45, first and second switching holes 46 and 47, a ball installation room 48, a switching ball 49, first and second paths 50 and 51.
Casing 41 includes an inflow opening 18A, first and second outflow openings 18B and 18C.
Inflow opening 18A is formed at a central portion in the direction of an axis line, and first and second outflow openings 18B and 18C are formed on opposite sides in the direction of an axis line at right angles to the axis.
Impeller 42 is installed inside of casing 41. Bi-directional pump electromotor 43 gives a turn to impeller 42 in a positive or a reverse direction, and first and second paths 50 and 51 are formed on both sides of first and second outflow openings 18B and 18C, respectively. First and second sleeves 44 and 45 are respectively inserted into both sides of first and second outflow openings 18B and 18C, and include first and second switching holes 46 and 47, respectively.
Switching ball 49 is disposed in ball installation room 48 which is disposed between first and second sleeves 44 and 45, and closes either first switching hole 46 or second switching hole 47 depending on whether it is in the heating or hot-water mode.
Bi-directional pump 18 is so installed inside of the gas boiler, as shown in FIG. 1, that first outflow opening 18B is disposed at a lower portion thereof and that second outflow opening 18C is disposed at an upper portion thereof. Bi-directional pump 18 operates as follows depending on the operating mode.
During the heating mode of the gas boiler, as shown in FIG. 4, bi-directional pump electromotor 43 gives a turn clockwise to impeller 42. When impeller 42 rotates clockwise, the pressure of the water which flows into ball installation room 48 via first path 50 is higher than that of the water which flows into ball installation room 48 via second path 51, so that switching ball 49 moves to the direction of first switching hole 46 and closes first switching hole 46 while opening second switching hole 47 disposed on the opposite side. Consequently, in the heating mode, the heating water flows from heat exchanger 19 into bi-directional pump 18 via inflow opening 18A, and then flows from second outflow opening 18B into heating water supply pipe 20.
During the hot-water mode of the gas boiler, as shown in FIG. 3, bi-directional pump electromotor 43 gives a turn counterclockwise to impeller 42. When impeller 42 rotates counterclockwise, the pressure of the water which flows into ball installation room 48 via second path 51 is higher than that of the water which flows into ball installation room 48 via first path 50, so that switching ball 49 moves to the direction of second switching hole 47 and closes second switching hole 47 while opening first switching hole 46 disposed on the opposite side. Consequently, in the hot-water mode, the heating water flows from heat exchanger 19 into bi-directional pump 18 via inflow opening 18A, and then flows from first outflow opening 18C into roundabout pipe 26.
As described above, during the warm-water mode, bi-directional pump 18 has the revolution direction thereof which is in opposition to that found in the heating mode, and switching ball 49 moves according to the revolution direction of bi-directional pump 18 to change the outflow direction of the heating water.
However, when the user selects and switches over from one mode to the other while the gas boiler is operating, switching ball 49 disposed inside of bi-directional pump 18 to adjust the flow of the heated water, abruptly moves from one side to the other side to collide with first switching hole 46 or with second switching hole 47, and thereby frequently generating a shock noise.